1. Field of the Invention
The present invention relates to a semiconductor device having a thick wiring line with a hole, and a manufacturing method thereof.
2. Description of the Related Art
As shown in FIG. 22, a semiconductor device with a multilayered structure sometimes requires thick wiring lines 111 and 112 in order to supply a large current. Wiring lines which are electrically isolated from the thick wiring lines 111 and 112, particularly vertical wiring lines such as vias 113 may be interposed between the thick wiring lines 111 and 112. In this case, as shown in FIG. 23, a wiring width X of the thick wiring lines 111 and 112, a width Y of the via 113, an alignment margin for a distance Z between the thick wiring line 111 or 112 and the via 113, and the like together increase the area of the semiconductor device.
Even a magnetic memory device such as an MRAM (Magnetic Random Access Memory) having an MTJ (Magnetic Tunnel Junction) element utilizing the tunnel magneto-resistance (to be referred to as TMR hereinafter) requires a thick wiring line at a given portion, and suffers the same problem as that of the semiconductor device.
That is, as shown in FIG. 24, in the magnetic memory device, an MTJ element 130 as a memory element is arranged at the intersection of a bit line 127 and word line 136, and data is written in the MTJ element 130. In write, a large current must be supplied to the bit line 127 and word line 136. For this purpose, the wiring widths of the bit line 127 and word line 136 must be thick to a certain degree.
In general, as shown in FIG. 25, the bit line 127 and word line 136 as write wiring lines must cover the MTJ element 130. The MTJ element 130 is often elongated for optimization of the magnetic domain. When the MTJ element 130 is elongated in a direction (direction indicated by an arrow) in which the word line 136 runs, a wiring width Q of the bit line 127 must be made large in accordance with a width P of the MTJ element 130.
In this manner, the device area also increases in the magnetic memory device owing to large wiring widths of the bit line 127 and word line 136, similar to the semiconductor device.